Nail gel curing apparatus which operate by using a plurality of light emitting diodes (LEDs) operating at an ultra-violet (UV) wavelength suitable for curing gels of the type applied to fingernails for decorative purposes are well known. For example U.S. Patent Application Publication No. 2011/0036997 discloses ultraviolet equipment which utilize LEDs which generate a UV wavelength suitable for the curing of a gel applied to the fingernail of a user. By placing the fingers into the unit, the fingernails are irradiated with a UV light which results in the gel applied to the fingernails being cured.
However, as is typical in the prior art, the source of the UV radiation, whether LEDs or other source of UV radiation, is arranged so that the fingernails are irradiated from above. Although such prior art devices are suitable for curing gel on the fingernails of the four fingers of the hand, the thumbnail typically does not receive the same amount of direct UV illumination which results in the gel on the thumbnail not being adequately cured, or which requires the user to place the thumb into the unit either before or after the fingernails of the four fingers have been exposed to the UV irradiation for curing of the gel thereon.
The reason the thumbnail does not receive adequate irradiation is due to the anatomy of a typical hand in which when the four fingers are extended and the thumb is extended, the four fingernails lie in approximately the same plane and are spaced relatively closely to one another. However, the thumbnail is spaced apart from the other four fingernails, and lies in a plane which can be almost perpendicular to the plane of the four fingernails.
The following are the results of this hand repositioning:                1. Customer must change hand position, making a first with the thumb extended straight out, facing upwards. Incorrect positioning of thumbs results in potential service failure.        2. Curing thumbs separately doubles the amount of time the curing process takes, thus lengthening total service time.        3. Normal sequence of application is disrupted, also lengthening total service time, and creating opportunity for application mistakes.        
As a result, the length of exposure to UV light doubles as compared to the invention as set forth in the following tables:
TABLE 1Application & Curing with a prior art UV LED Light:StepsActionCure Time 1Apply Base Coat30 SecondsCure 4 Fingers (2-5) 2Apply Color Coat30 SecondsCure 4 Fingers 3Apply 2nd Color Coat30 SecondsCure 4 Fingers 4Apply Top Coat30 SecondsCure 4 Fingers 5Wipe Residue 6Apply Base Coat30 SecondsCure Thumb (finger 1) 7Apply Color Coat30 SecondsCure Thumb 8Apply 2nd Color Coat30 SecondsCure Thumb 9Apply Top Coat30 SecondsCure Thumb10Wipe Residue10 StepsTOTAL CURE TIME (UV Light 4 Minutes Per HandExposure):
TABLE 2Application & Curing using the invented UV LED Light:StepsActionCure Time1Apply Base Coat30 SecondsCure Fingers 1-5 (including thumb)2Apply Color Coat30 SecondsCure Fingers 1-53Apply 2nd Color Coat30 SecondsCure Fingers 1-54Apply Top Coat30 SecondsCure Fingers 1-55Wipe Residue5 StepsTOTAL CURE TIME (UV Light 2 Minutes Per HandExposure):
The present invention overcomes the limitations of the prior art by including an additional UV light source which, for the thumbnail, is at the same relative position, i.e., angle and distance, as the UV source for the fingernails.